Last January, 2017 Next Gen ATP Finals champion Hyeon Chung made his biggest breakthrough yet by reaching the semi-finals of the Australian Open. When the US Open rolled around, he was No. 23 in the ATP Rankings, making him a seeded player in the main draw of the US Open.

But on Monday, World No. 151 Chung had to compete in the first round of qualifying in Flushing Meadows, where he rolled past Austrian Sebastian Ofner 6-3, 6-3 in 74 minutes.

Chung missed five months of the season due to a back injury, and he has played just three events since February, all of which have come on the ATP Challenger Tour. The 23-year-old will next play Italian Stefano Napolitano, who advanced past American Sam Riffice 6-2, 6-4 after one hour and 22 minutes.

Third seed Soonwoo Kwon overcame a brief rain delay and American JC Aragone, moving into the second round with a 6-4, 1-6, 6-4 triumph. Play was suspended at 2-2 in the third set as both men battled on a humid day, but it was Kwon who finished stronger, breaking to win the match.

“It was actually beneficial for me for being able to recover after the rain, so it was actually fortunate for me to have it,” Kwon said.

Kwon cracked the Top 100 of the ATP Rankings for the first time on 5 August, and he currently sits at a career-high No. 90. The 21-year-old lost in the first round of qualifying in New York last year, which was his debut at this tournament.

“The only pressure that I have is I really want to get into the main draw and that’s my only goal for now,” Kwon said.